R语言修正数据集字段拼写错误的方法求助

问题背景 #

我的数据集Inventory的mat_source字段应仅包含3种固定值：ark、bg、brnl，但录入时出现拼写错误。通过以下R代码查看了列的唯一值及对应计数：

glimpse(Inventory)
# Rows: 4,860
# Columns: 5
# asset_ID   <dbl> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 3…
# length     <dbl> 500, 170, 480, 284, 30, 500, 270, 476, 395, 80, 500, 500, 500, 110, 500, 363, 254, 113, 500, 200, 27, 583, 5…
# age        <dbl> 6.120548, 5.967123, 8.824658, 9.824658, 3.808219, 3.095890, 6.797260, 2.816438, 4.975342, 18.904110, 14.1315…
# mat_source <chr> "ark", "bg", "brnl", "brnl", "bg", "brnl", "brnl", "ark", "brnl", "ark", "brnl", "ark", "ark", "brnl", "brnl"…
# con_num    <dbl> 1, 1, 2, 2, 3, 1, 4, 4, 1, 2, 1, 1, 4, 3, 1, 4, 3, 3, 1, 3, 2, 2, 1, 3, 3, 3, 1, 3, 4, 3, 4, 4, 2, 3, 3, 3, …

# 查看唯一值
unique(Inventory$mat_source)
# [1] "ark"   "bg"    "brnl"  "arl"   "arkm"  "black"

# 按mat_source分组计数
Inventory %>% group_by(mat_source) %>%
  summarise(Count = n())
# A tibble: 6 × 2
# mat_source Count
#   <chr>      <int>
# 1 ark         1394
# 2 arkm           6
# 3 arl            1
# 4 bg          1361
# 5 black          4
# 6 brnl        2094

需要将arkm、arl替换为ark，black替换为bg，但之前尝试的方法未成功：

# 错误：fct_recode参数顺序颠倒，应为"正确值" = "错误值"
mutate(Inventory, mat_source = fct_recode(mat_source, "arl" = "ark"))

# 错误：仅处理了arl，且替换值写错为alk，后续因子转换逻辑无效
Inventory$mat_source <- ifelse(Inventory$mat_source  == "arl", "alk", Inventory$mat_source) 
Inventory <- Inventory %>% mutate(mat_source = factor(mat_source, levels = mat_source)) 

正确处理方法 #

方法1：使用fct_recode（因子重编码） #

注意fct_recode的参数顺序是**"目标值" = "原始错误值"**，需覆盖所有错误项：

library(forcats)
library(dplyr)

Inventory <- Inventory %>%
  mutate(mat_source = fct_recode(mat_source,
                                 "ark" = "arl",
                                 "ark" = "arkm",
                                 "bg" = "black"))

方法2：使用case_when（灵活条件替换） #

逻辑清晰，适合多条件判断场景：

Inventory <- Inventory %>%
  mutate(mat_source = case_when(
    mat_source %in% c("arl", "arkm") ~ "ark",
    mat_source == "black" ~ "bg",
    TRUE ~ mat_source  # 保留原本正确的取值
  ))

方法3：使用recode（针对字符型列） #

若mat_source是字符型而非因子，直接用dplyr::recode：

Inventory <- Inventory %>%
  mutate(mat_source = recode(mat_source,
                             "arl" = "ark",
                             "arkm" = "ark",
                             "black" = "bg"))

验证结果 #

执行替换后，再次检查唯一值和计数确认修正效果：

unique(Inventory$mat_source)
# 应仅返回 "ark" "bg" "brnl"

Inventory %>% group_by(mat_source) %>% summarise(Count = n())
# 预期结果：
# mat_source Count
#   <chr>      <int>
# 1 ark         1401  # 1394+6+1
# 2 bg          1365  # 1361+4
# 3 brnl        2094

内容的提问来源于stack exchange，提问作者Natalie Storm